The present invention relates in general to a corkscrew and in particular to a corkscrew with a simplified arrangement to pierce into a cork and extract it from a bottle by way of a more effective means for centering the helical body of the corkscrew with respect to the cork by simple single-direction turning motion.
Corkscrews are well known in the art. The marked differences between the existing corkscrews are in their mechanical structures. Some do not provide centering means at all while others, though providing centering means, position such centering means too far above the cork to be extracted, to function well.
U.S. Pat. No. 4,570,512, to Pracht introduced a spring-loaded piston housed in a sleeve-like body. At its position of rest, the corkscrew blade is completely shielded the corkscrew is believed to be safe and not likely to cause blade injuries with its tip. Unfortunately this may not be so, since the sleeve-like body is only weakly held in position by a releasing spring, and unconscious withdrawal of this sleeve-like body when being pressed accidentally or unknowingly can cause injuries to a user. This type of corkscrews is even more dangerous than that with exposed corkscrew blades as to which users normally pay special attention.
UK Patent Application No. 9113364.5, filed by the present inventors at the filing Date of Jun. 20, 1991, discloses an improved corkscrew configured to avoid the possible injuries to users and to center the corkscrew in respect to the cork, and including a simplified housing means and a centering means with a track means being formed at the central portion thereof for receiving the helical body of the corkscrew means passing slidably therethrough. In operation, the centering means is initially located at its lowest position in the housing means just on top of the bottle to be uncorked. While the helical body is turned clockwise the helical body shall pierce into the cork with the axis of the helical body substantially along or parallel closely to the axis of the cork owing to that the centering means is very close to the cork so as to avoid the departure of the helical body from the line substantially along or parallel closely to the axis of the cork during piercing. Upon continued rotation, the helical body shall penetrate through the cork. The centering means as well as the cork shall move up along the helical body till the extraction of the cork from the bottle is completed when the centering means together with the extracted cork move to the upper portion in the housing means.
It has been brought to the inventors' notice that in the operation of the improved corkscrew disclosed in the UK patent application No. 9113364.5 the centering means should start to move up along the helical body together with the penetrated cork when the helical body comes to the lowest position and is further turned while at this position. However, it is found that at any moment during the downward movement of the helical body to the lowest position if the helical body stands for some reason and continues being turned in situ, the centering means shall start to move up along the helical body immediately and the cork remain unpenetrated in situ. After that, as soon as the helical body continues being pressed and turned in the original direction, the cork shall be penetrated through and moved up with a gap between the cork and the centering means when the helical body comes to the lowest position and continues being turned in the same direction. The gap between the cork and the centering means will appear more or less during the turning of the helical body in the same direction even if there is no stop during the downward movement of the helical body because of the loss of tangential friction (slippage) between the cork and the internal surface of the bottle neck. This loss of tangential friction causes the cork to rotate along with the helical body occasionally and move up slower than the centering means moves up. In other words, they would not move up synchronously or simultaneously, so that the gap would always exist between the cork and the centering means. As a result of the undesirable gap, the housing means has to be long enough to contain the centering means, the extracted cork and the gap caused from time to time. Sometimes, the gap caused is so large that the cork may not be fully extracted from the bottle when the centering means moves up to the highest position and terminates the operation.
In view of the foregoing, it is an object of the present invention to provide an improved centering means to eliminate the gap between the extracted cork and the centering means while they are moving up such that the housing means needs no additional length to contain the undesirable gap and the cork will certainly be extracted fully into the housing means.
It is another object of the present invention to provide a corkscrew with less danger but more efficient and reliable to use and simple structure to manufacture.